Melt butter in a large pot over medium heat. Add sliced onions and cook, stirring occasionally, for 30-40 minutes, or until deeply caramelized.
Stir in garlic and cook for 1 minute. Add flour and cook for another minute, stirring constantly.
Pour in beef broth, dry red wine, thyme, bay leaf, salt, and pepper. Bring to a boil, then reduce heat and simmer for 20 minutes.
Preheat broiler. Ladle soup into oven-safe bowls. Top each bowl with a slice of crusty bread and a generous amount of grated Gruyère cheese.
Broil for 2-3 minutes, or until cheese is melted and bubbly.
Remove from broiler and let cool slightly before serving. Garnish with fresh parsley if desired.
Serve immediately and enjoy the rich and satisfying flavors of this classic soup.
Made this for a dinner party, and it was a hit! Everyone loved it. The bread got a little soggy, so next time I might toast it separately for a bit longer.
Very good! I added a bay leaf to the broth for extra flavor, and it made a nice difference. The cheese melted perfectly. A comforting classic.
Pretty good! I enjoyed the soup, but it was a bit too salty for my taste. I would suggest using low-sodium broth to control the saltiness. Otherwise, a great recipe!
Wow! Just wow! This soup is a culinary masterpiece. The caramelized onions are the star, and the broth is simply divine. I followed the recipe exactly, and it was perfect.
The onions burned before they caramelized properly. The broth was also quite bland, even after adding salt and pepper. Disappointed.
